A horse spooked by a rattlesnake got its leg caught in a wooden bridge off Calistoga Road on Wednesday, Rincon Valley fire officials said.

The animal injured a rear leg in the 1:40 p.m. fall on Cleland Ranch Road, a private dirt road off Calistoga between Plum Ranch and St. Helena roads, authorities said.

When the animal was spooked it stepped down into a center portion of a wood slot bridge and fell to its side, getting its hoof stuck between the slats, Rincon Valley Fire Capt. Fred Leuenberger said.

A veterinarian lightly sedated the animal and firefighters used a saw to cut through some of the wood and free the leg, Leuenberger said.

The horse was part of a group of about a dozen horseback riders on the property. Rescuers moved the horse off the bridge to solid ground and the animal was able to stand up on its own, Leuenberger said. It didn't appear that the horse broke a bone, and its rider was uninjured, he said.

The snake remained nearby as the crews worked, coiled and calm, Leuenberger said.